Crystalis

Agree with many mentioned above.

BG, Fallout 1/2, System Shock, Planescape Tourment, KotoR

Also consider:

Arcanum, Diablo II

Definately Those Games (they are probably the best WRPG's out there)

Consider also: Icewind Dale 1 & 2 (awesome RPG, more hack n slash oriented but with great stories, some good characters, and amazing feeling of Wild Frozen Lands)

Sid Meier's Alpha Centauri (great strategy game) , Panzer General II

Also consider Max Payne 1 and 2.

This list is full of win. Any of these games are worth fullprice, but can be purchased cheap. Plants vs. Zombies is especially interesting in your case, since you like strategy games (though I'd say it's a tower defense game) and it should run on almost any computer that hasn't broken down yet.

Diablo II..man u're going to njoi a lot if u try this one out.
or else the second option Warcraft iii...
njoi ur time either

fps-call of duty 1 or medal of honor.

Counter-Strike ..or... a DVD full of SNES roms =D

Then hug the good woman and get her to buy you a new laptop :) 

Cant hurt to try!

Of all the stuff listed here so far, what games are you looking at?

So many interesting games, but I bought CIV3 complete edition. I actually got bored with it quite soon. It just does not feel right after CIV4. So next tries would be alpha centauri, baldurs gate 2, master of orion 2 and fallout 1/2.

Too bad that I could not find AC,BG or MOO anywhere. So it will propably be fallouts from gog. 4$ each, damn. ;)

Planescape Torement
Rome: Total War
Age of Empires 2
Rise of Nations
Baldurs gate 1 & 2
Neverwinter Nights
Morrowind
Unreal Tournament
Star Wars: KoToR 1 & 2
Call of Duty 1
Fallout 1 & 2
Starcraft
Warcraft III
Mount and Blade (relatively new but low spec)
Darwinia
Uplink

You say you've played through Deus Ex enough, but have you tried all the mods? There were some pretty good SP mods out there.